Mostra calendário edittext

Button btn = (Button) findViewById(R.id.button1);
final EditText editText = (EditText) findViewById(R.id.editText1);

btn.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Calendar c = Calendar.getInstance();
        int day = c.get(Calendar.DAY_OF_MONTH);
        int month = c.get(Calendar.MONTH);
        int year = c.get(Calendar.YEAR);
        editText.setText(day + "/" + (month + 1) + "/" + year);
    }
});